Gremlins are mythical creatures who inhabit physics labs and introduce anomalous results into experiments. The problems attributable to gremlins are subtle and go beyond the usual kinds of experimental problems. I spent a large part of my sabbatical troubleshooting several experimental setups at the University of Queensland in Brisbane, Australia and the University of Illinois at Champaign-Urbana, Illinois. Some of these problems were subtle enough that gremlins were starting to seem to be a real thing. I will present some of the problems encountered and the process of solving them.